SEMICONDUCTOR MANUFATURING EQUIPMENT HAVING OPPOSITE PRESSURE PREVENTION UNIT

A semiconductor fabrication apparatus having an opposite pressure prevention unit is provided to prevent damages due to back pressure by restraining the generation of the back pressure due to interruption of a vacuum pump. A chamber includes a predetermined processing space. A first vacuum pump is connected to the chamber through a vacuum line in order to form a vacuum state of the chamber. A second vacuum pump is installed between the chamber and the first vacuum pump. A back pressure prevention unit(30) is installed at a lower part of the second vacuum pump in order to offset the back pressure. The back pressure prevention unit includes a diaphragm having a through-hole(34), a rotary plate(33) having the same size as the through-hole, and a fixing hole(37) formed at both sides of the through-hole.